How to build a concentrated advanced packaging portfolio using [[Bill Ackman]] style conviction. **Core principle:** Own one or two names max. Concentration forces you to really understand the business. No hedging with marginal bets. **Primary position: [[Amkor - AMKR]]** This is the "show up and get paid" business. Real cash flows, direct exposure to [[Packaging Capacity Bottleneck]], customer-backed capacity expansion. If you can only own one packaging name, this is it. **Optional second: [[ASE Technology - ASX]]** Scale leader with similar characteristics. Only add if you want redundancy, not if you're seeking different exposure. Owning both is like owning two railroads on the same route. **What to avoid:** - [[Kulicke & Soffa - KLIC]]: Too cyclical for concentration. Earnings volatility violates the durable cash flow requirement. - [[BESI - Hybrid Bonding Leader]]: Great tech, but optionality-driven. Not value-first. - Intel: Too many moving parts. Packaging alone doesn't determine outcome. **Ackman-style question:** "What has to be true for this to permanently impair my capital?" For AMKR, the answer is observable: structural demand collapse, customer vertical integration at scale, or permanent pricing power loss. None are happening quietly. **Position sizing:** If truly concentrated, 45-55% in AMKR. If adding ASX, split 50/50 or tilt 60/40 toward your highest conviction name. This approach only works if you have deep conviction and can stomach volatility without selling. Links: [[Advanced Packaging MOC]], [[OSAT Value Investing Framework]], [[Bill Ackman]], [[Investing Principles]] --- #investing #kp